Electrochemical reactions, e.g. oxygen reduction (ORR), hydrogen evolution (HER) and oxygen evolution reaction (OER), are key to energy conversion and storage. For example, ORR is a determining step for fuel cells; HER and OER are for water splitting; Combination of ORR and OER can form a metal-air battery. Up to now, platinum (Pt) exhibits the best performance, and Pt/C is the commercial cathode catalyst for the reactions. However, the large-scale use of Pt is not implementable because of the high price and limited supply. Therefore, numerous efforts have been devoted to search for non-Pt catalysts. Carbon is one of the candidates.
Herein, we recently demonstrate a new defect mechanism of carbons for oxygen reduction reaction (ORR). It is predicted by the first principle calculations that a type of 585 defects on graphene (G585) is more effective than N-doping for ORR, and our experimental investigations show strong support to this theoretical prediction. This new mechanism has also been demonstrated for other electrochemical reactions such hydrogen evolution reactions (HER) and oxygen evolution reactions (OER).
Dr Xiangdong Yao is a full Professor of Energy Materials at Griffith University. In 2000, he came to The University of Queensland where he was granted the PhD degree in Materials Engineering in 2005, working on the computational modeling for microstructure formation in light metals. Since November 2009, he joined Griffith University as an Associate Professor and the group leader of advanced energy materials, and promoted to full Professor in late 2012. Dr Yao has made a number of significant contributions to these areas and has published over 150 articles in peer-reviewed journals. He has chaired and co-chaired over 10 international conference and serves as Editorial Board members for three international journals. He has been awarded several research Fellowships, including an ARC Australian Research Fellowship and an ARC Postdoctoral Fellowship (Industry).